Process for the manufacture of oxycarbid of barium.



No. 888,956. PATENTED MAY 26, 1908. R. BATTISTONI & R. ROTELLI. PROCESSFOR THE MANUFACTURE OF OXYGARBID 0F BARIUM.

APPLIUATION 11.21) JAN. 14, 1905.

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I pyz'lnessar:

UNITED STATES PATENT OFFICE.

ROD OLFO BATTISTONI, OF ANCONA, AND ROMOLO ROTELLI, OF VENICE, ITALY.

Specification of Letters Patent.

Patented May 26, 1908.

Application filed January 14, 1905. Serial No. 241,155.

of Barium, of which the following is a speci-\ fication.

The object of this invention is a process for the manufacture of a newproduct which -is composed of a mixture of 10 to 12 per cent. 3 to 5 percent. Ba(CN) 80 to 85 per 138.0,, cent. BaO. This product of oxycarbidof barium is designated by the name baryundum. It is distinguished fromBaC as well as from BaO by its color; its crystalline structure, theeasine ss with which it is by drated and the disengagement of NH whichis effected by the hydratation of Ba(ON) This product is obtained in theelectric furnace by the process described hereafter by plrleviouslymixing the BaCO with extremely e carbon and submittin it in a hot stateto the-electrolytic efiect ofa direct current. The electrolysis of thenatural or artificial carbonate of barium in a molten state, and theaddition of carbon in a proportion of 3 to 4 per cent. in its finestpossi le state are the two essential characteristics of our process. Thelatter has indeed nothing in common with the manufacture of carbid ofbarium because the latter is not based upon the electrolysis of thecarbonate of barium but on the reduction of the BaCO bygreat %uantitiesof coal according to the e uation aCO +4C=BaC +3CO It has not gin commonwith the manufacture of pure BaO or of BaO mixed with'BaOO, as thelatter is obtained with ordinary flame furnaces by a thermic but not. byan electrolytic effect. Furthermore the carbon added in the present caseplays quite another part than in the cited process.

In the manufacture of carbid of barium the carbon acts as a reducingagent and in the manufacture of oxid of barium only as a combustiblewith a view of developing and maintaining a determined uniform heat inthe mass contained in the furnace. In our process on the contrary thecarbon acts as a catalytic substance, as a conducting means for theelectric current and offers a whole system of bearing surfaces fortheregular develo ment of the ions freed by the current.

T e oxycarbid of barium can be manufactured from the natural carbonateof barium as well as from the artificial carbonate obtained in theextraction of sugar from molasses by means of baryta. In the latter casethe carbon necessary for the o eration ought to be added to thecarbonate 0 barium before the latter is conveyed to the filter process.In this manner cakes are obtained which are composed of an' extremelyhomogeneous mixture of carbon and carbonate of barium which is one ofthe principal conditions for the good success of the operation in theelectric furnace. The cakes thus obtained are dried and immediatelyintroduced into the electric oven. J

Referring to the drawing, the electric oven is preferably composed of ametallic envelop 20 lined on its inside with fire resisting brickworkwhereupon a mass is extended which is essentially composed of carbonateof barium. The movable bottom 21 receives the lower electrode 22.Connected to the cover 23 is the escape duct for the CO gases. Thecharging of the furnace as well as the maneuvering of theupper-electrode 24 are effected in any desired manner in the presentcase for 30 and 31 are current conductors, 32 a liquid rheostatinterposed in the circuit.

The movable bottom of the furnace is provided with Wheels 33 so that thebottom can be loaded at any desired place with the material to betreated and can then be rolled on rails 34 perpendicularly under thefurnace. The rising at the convenient height is effected by means of ahydraulic piston 35 or any other convenient contrivance. v

The escape of the oxids of carbon is assisted by a suction device 36 theCO whereof is furthermore used after removalof dust and after washingfor effecting the decomposition of the saccharate of barium.

The electrolytic treatment is carried out in such a manner that thefurnace is first used as a voltaic arc furnace and at the end of theiout in both phases in a different manner.

The obtained product is composed, as already stated, of a homogeneousmixture of oxid of barium and carbon with prevalence of the former, andhas received in trade the name of baryundum. In order to increase theproportion of oxid to a maximum figure, it is before all thingsnecessary that the amount of carbon in the cake of carbonate of bariumbe sufficient for allowing of the catalytic action and the followingdecomposition of the carbonate taking place. As this special effect ofthe carbon depends upon the finely divided'state wherein the carbon isin the mass, itfollows that the more finely divided the carbon, 11. 6.,the finer the introduced amount of carbon is taken, the smaller must bethe amount necessary for the complete success of the operation.-

. In certain cases it would be advantageous to replace the carbon powderby carbon produced by the calcination of the juice of sugar or of otherorganic substances, this being carried out by retaining in the cakes ofcarbonate by a more or less long washing operation, that amount of sugaror of organic substances which is necessary for the success of theoperation. i The roduct leaves the furnace in the form of bloc s whichare allowed to cool in suitable apparatus adapted to allow of the heatdisen gaged during this cooling operation, being used for dryin thecarbonate cakes.

We find Ba CN) in our product without any special introducing of'thenitrogen. It is supposed that the little quantity of Ba (CN) that wefind in our finished products is due to the BaC which when it is in thestate of i eous liquefaction, acts asvery strong re ucer, and a smallpart of the nitrogen of the air that leaks inside the furnace in contactwith BaO combines with it to give Ba(CN) The production of this cyanidis nearly constant if mineral barium carbonate (whitherite), is used andincreases a little and is variable if barium carbonate taken from thesugar refinery is used, and this is because the carbonate at the momentof its formation carries with it a part of the organic matters that arefound in the sugar juices.

to the electrolytic 1 ical operation are as follows :BaCO +current=Ba+CO CO does not exist in the free state and it separates in CO and O,the atom of ox gen findin itself in immediate contact wit the metal a,oxidizes it, giving origin to BaO, so:

BaCO current Ba CO Ba+CO +O=BaO+OO But we have added and well mixed acertain quantity of carbon (4%) so as to carry the action of the currentall through the mass.

Gradually the mass transforms from BaCO into BaO and CO and stops thefunction of the carbon that under the action of the high temperaturecombines with BaO, giving place to the formation of BaO,. Such formationis limited and proportional to the quantity of carbon that is containedin the mass. The BaO,, as stated above, in the melted condition, has avery high reducing power, so, for the nitrogen of the air that is in thefurnace, and for the nitrogen contained in the. organic substances thatare introduced in the carbonate, whereby is obtained a certain quantityof Ba.(CN), chan cable between the 2 and 5% according to t e quantity ofor anic matter contained in the barium earonate. I

It is furthermore advantageous with a view ofallowing of theelectrolytic decomposition of the carbonate of barium being,

carried out with as small an expense of energy as possible to add to thenatural or artificial carbonate 5 to 6 per cent. of a mixture ofalkaline salts as for instance those which are obtained b calcining themother lyes obtained in t e extraction of sugar from the molasses. Thesesalts act as a flux powder at the beginning of the operation as theyrender the mass more liquid and more suitable for the electrolysis,while they act in the following manner in the later course of theoperation.

1st reaction BaCOH-K CO +current=BaC0 +K O+CO 3rd reactionBaO-i-IQCOH-current: O+K2O+C02 i. e. the K 0 first freed by the currentexpels the BaO from its combination with the CO thus furnishing chemicalenergy which otherwise would be done by the current. This has as aconsequence a considerable saving of electric energy as the electrolyzinaction'of the current is exerted on K 00 w ich is always renewed and asa matter of fact is found more easy to electrol ze than the BaOO When wework wit the aid of an alkaline by Letters Patent is as follows 1, Aprocess for the manufacture of a product, oxycarbid of barium,comprising ten to twelve per cent. of carbid of barium, three to fiveper cent, of cyanamid of barium and eighty to eighty-five per cent. ofoxid of barium, which comprises mixing with barium carbonate adetermined amount of.finely divided carbon, melting the said mixture inan electric furnace and then submitting the meltedmixture to theelectrolytic action of an electric current.

2. process of the manufacture of a product, oxycarbid of barium,comprising ten to-twelve per cent. of carbidof barium, three to five percent. of cyanamidof barium and eight to eighty-five per cent. of oxid ofbarium w or carbonate a flux, and a determined amount of finely dividedcarbon, meltin the said mixture in an electric furnace an mitting themelted mixture -to the electro- 1 lytic action of an electric current.30

ch comprlses mixing with barium 25 then sub- In testimony whereof wehave hereunto set our hands in presence of two witnesses.

Witnesses VINOENZO SUcoI, UMBETO NICOLAI.

